Steam-engine air-pump.



T. THOMPSON. STEAM ENGINE AIR PUMP.

APPLICATION rum: an. 31, 1900.

Patented Aug. 16, 1910.

W iinwses. I nventor:

By lub'fliqtor' neyl.

THE mzRRls PETERS cc.. WASHINGTON, o. c.

THOMAS THOMPSON, OF BLACKI-IEATH, ENGLAND.

STEAM-ENGIN E AIR-PUMP.

Specification of Letters Patent.

Patented Aug. 16, 1910.

Application filed March 31, 1900. Serial No. 10,962.

To all whom it may concern:

Be it known that I, THOMAS THOMPSON, a subject of the Queen of GreatBritain and Ireland, residing at Arlicote, Westcombe Hill, Blackheath,in the county of Kent, England, have invented certain new and use fulImprovements in or Connected with Steam-Engine Air-Pumps, (for which Ihave made application for patent in Great Britain, No. 1,923, datedJanuary 30, 1900;) and I do hereby declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

This invention for improvements in or connected with steam engineairpumps relates to pumps of the class known as valveless pumps and inwhich the air or vapor and the water are separately dealt with, andconsists in forcing or admitting water immediately before thecommencement of the upstroke on to the top of the piston to form apacking or water seal, in forcing a small quantity of water togetherwith the air through the delivery valves and in arranging above thevalves 2. water chamber in which the water is kept at a constant level.

The amount of water admitted at each stroke of the piston is regulatedby a stop cock adjusted so that the amount admitted slightly exceeds theamount sufficient to keep the piston sealed and the water level in thewater chamber constant. Any excess passes off by the overflow.

By this invention the air pump can be driven at a much higher speed thanpumps that deal with both the air and water from the condenser while theadvantages of such pumps are retained. The water in the condenser isremoved by a separate pump and is thus dealt with practicallycontinuously and not by shocks at the end of the air pump stroke.

The invention consists in the novel construction, arrangement andcombination of parts as hereinafter fully described, illustrated in thedrawing and pointed out in the appended claims.

In the drawing :Figure 1 is a vertical central section of a steam engineair pump constructed according to this invention. Fig. 2 is a similarview showing a slightly modified construction.

The vertical air pump cylinder a is pro vided with a piston 6 whoseupper surface forms the working face. The lower end of the cylinder atis connected by the ports d and passage with the condenser c at somepoint well above any water likely to remain in the condenser. The portsd are of such height in the cylinder that they are above and completelyuncovered by the piston Z) when in its lowest position as clearly shown.The piston rod is provided with passages 2'.

m is a tubular extension of the cylinder for the trunk piston rod n andis provided with a groove or channel Z.

'0 is a small chamber arranged immediately over the cylinder at andprovided with an overflow u; at a suitable level. The upper end of thecylinder at is surmounted by a perforated plate 4 whose perforations areclosed by balls 8 kept in position by the movable cover plate t. Thepassages 71 on the trunk piston rod 11. working in conjunction with thegroove Z are arranged to deliver the water under pressure below thepiston Z) at the end of the down stroke and as it completes such strokethe piston forces this water, and any water that leaked past it duringthe previous upstroke, around itself and on to its upper face throughthe ports cl. Any sealing water leaking past the piston collects in thebottom of the pump and is returned to the top of the piston at the endof its down stroke as above stated. In this arrangement the water supplyis taken from the chamber 71 above the delivery valves by a pipe w sothat the same sealing water is used over and over again, the waste beingmade up from a supply controlled by any suitable means such as a ball orfloat valve.

In the modification shown in Fig. 2 the piston rod e is above the pistonand the passage 2" in the piston rod 0 working in conjunction with thegroove on channel Z in the tubular extension m of the cylinder arearranged to deliver the water direct from the chamber a to the top ofthe air pump cylinder when the piston is at the bottom of its stroke. 'wis an overflow pipe for the chamber 0 and w is a drain pipe leading fromsaid chamber. a is the condenser. a is the air pump cylinder; 0 thepassages and d the ports connecting the cylinder with condenser 0 b thepiston; m the tubular extension on the cylinder, '1" perforated plate oncylinder a; t the cover plate keeping the balls 8 in position, whichballs close the perforations in plate r; h are outlet passages from thepiston rod.

It will be noticed that the leaka e of air into the pump past the pistonrod, is entirely prevented by the water gland constituted by the passageZ filled with water,

which thus forms a kind of packing, the excess pressure of water in thegland being equivalent to the vacuum in the, condenser added to the headof sealing'water;

When the piston in Fig. l'is near the bottom of its stroke the waterflows just below the piston into the annular enlargement 0'.

The water cannot fiow into the condenser on account of the abutment 0The source of the original supply of fluid in chamber '0 may be anentirely separate water supply controlled by a stop-cock or the watermay be supplied from the separate water pump on the condenser.

I am aware that fluids have been admitted into the cylinders of airpumps for sealing and other purposes and I do not claim to do thisbroadly.

What I claim and desire to secure by patent is 1. In an air pump of thecharacter described, the combination with a vertical cylinder, of apiston movable therein, said cylinder being provided with perforationsat such a height therein that they will be completely uncovered when thepiston is at the lowest point, a piston rod, a water chamber arrangedabove the cylinder, a condenser, a connection intermediate the latterand the cylinder and in constant communication with the perforations inthe cylinder and means for placing the water chamber in communicationwith the interior of the cylinder when the piston is at the lowest pointof its stroke. 2'."In 'anair pump of the character described, thecombination with a vertical cylinder, of a piston movable therein, saidcylinder being provided with perforations at such a height therein thatthey will be completely uncovered when the piston is at the lowestpoint, a water chamber arran ed above the cylinder, a piston rod provied with a port or passage adapted to communicate at its ends with theinterior of the water chamber and the interior of the cylinder when thepiston is at the lowest point of its stroke, a condenser, and aconnection intermediate the latter and the cylinder and in constantcommunication with the perforations in the cylinder for the purpose setforth.

In testimony whereof I aflix my signature, in presence of two witnesses.

THOMAS THOMPSON.

